The effect of arthroscopic capsulotomy and repair on native resting hip joint forces using a non-destructive extra-articular method

Previous methods for measuring intra-articular forces require significant soft tissue dissection and intra-articular insertion of sensory instruments. This study demonstrates a minimally invasive method of measuring native resting hip joint force without disrupting the soft tissue envelope. This method is then utilized to determine the effect of capsulotomy and repair on these forces. Twenty fresh-frozen human cadaver hemipelves were percutaneously instrumented with an iliac crest locking plate and retrograde femoral nail to allow for testing using a distracting force. Force–displacement curves were generated in the native state, and after joint venting, an anterior hip approach, capsulotomy, capsular repair and soft tissue dissections. Mean native resting hip joint force was 110.5 N (SD 54.3 N). Capsular venting resulted in a significant decrease in hip joint force compared with the native state (100.2 N, SD 45.2 N, P = 0.026). A further decrease in hip joint force was observed with a T-capsulotomy (79.9 N, SD 40.1 N, P < 0.001 compared with anterior hip approach), with restoration of these forces after capsular repair (84.8 N, SD 40.5, P = 0.014 versus T-capsulotomy and P = 0.67 versus anterior hip approach). Soft tissue dissection resulted in a large decrease in hip joint force compared with the hip’s native state (59.7 N, SD 28.4 N, P = 0.002). Taken together, the findings suggest that this method is effective in measuring hip joint force and may be more accurate than those requiring significant soft tissue dissection. Furthermore, the data suggest that capsular repair likely plays an important role in the restoration of biomechanical forces in the hip after capsulotomy.

Intrafat Sequestration of Artemisinin Disguised as a Purulent Collection during a Posterolateral Hip Approach

The posterolateral hip approach is the oldest and most used way to implant total hip arthroplasty. The anterior part of the oblique portion of this posterolateral approach corresponds more or less to the superolateral quadrant of the buttock in which the intramuscular injection of various drugs, including the compounds derived from artemisinin, is carried out. Thus, in a malarial endemic area where gluteal injections of the compounds derived from artemisinin are not rare, poor performance of an injection by the deposition of the product in the fat and not deeply in the muscle can be at the origin of the sequestration of the drug in adipose tissue and give the macroscopic appearance of a pus. The authors present a case of intrafat sequestration of artemisinin taken for purulent collection during a posterolateral hip approach for total hip arthroplasty.

Surgical Treatment of Intrapelvic Pseudotumour after Hip Resurfacing Arthroplasty: Case Report and Literature Review

Hip replacement is the surgery of the last century due to its impact on the quality of life. A pseudotumour is a rare complication of hip arthroplasty, and it is related to a metal-bearing surface. Pseudotumour is a challenging scenario for hip surgeons due to poor clinical outcomes. The patient consulted for hip pain and paresthesia in the left lower extremity, and analyses showed that the cause was a sizeable intrapelvic pseudotumour. A multidisciplinary team surgery was planned. At first, an infraumbilical approach was made to resect the intrapelvic-retroperitoneum portion of the pseudotumour. Then, a posterolateral hip approach was performed, to resect the remaining portion of the pseudotumour and revision arthroplasty. At five years of follow-up, there are no clinical or imaging signs of recurrence of the pseudotumour. Treatment evidence is limited to a series of cases and expert opinions; we encourage complete resection and revision arthroplasty.